Disney is hard at work bringing about the Robopocalypse. Behold the throwing bots, the brand-new batch of robots Disney can't wait to unleash into their parks. This new line of androids can throw a ball back and forth with a human guest and even juggle! Disney hopes they'll raise theme park audience participation to a new level, especially when the robots start throwing knives at people's heads.

Entertainment robots in theme park environments typically do not allow for physical interaction and contact with guests. However, catching and throwing back objects is one form of physical engagement that still maintains a safe distance between the robot and participants. Using a theme park type animatronic humanoid robot, we developed a test bed for a throwing and catching game scenario. We use an external camera system (ASUS Xtion PRO LIVE) to locate balls and a Kalman ﬁlter to predict ball destination and timing. The robot's hand and joint-space are calibrated to the vision coordinate system using a least-squares technique, such that the hand can be positioned to the predicted location. Successful catches are thrown back two and a half meters forward to the participant, and missed catches are detected to trigger suitable animations that indicate failure. Human to robot partner juggling (three ball cascade pattern, one hand for each partner) is also achieved by speeding up the catching/throwing cycle. We tested the throwing/catching system on six participants (one child and ﬁve adults, including one elderly), and the juggling system on three skilled jugglers.